Container and closure cap

ABSTRACT

A push-and-turn container and closure cap combination provided. Cap ( 1 ) has an inner skirt ( 3 ) with H ( 10 ) is a screw thread ( 4 ) which co-operates with a screw threaded neck ( 11 ) of the container, and a sprung outer skirt ( 5 ) which surrounds inner skirt ( 3 ). Container ( 10 ) has a locking ring ( 15 ) with two slots ( 16,17 ); cap ( 1 ) has two lugs ( 7,8 ) which engage in slots ( 16,17 ) when the cap ( 1 ) is fully screwed on to the container ( 10 ) and the outer skirt is in a first, rest position thereby preventing the cap from being unscrewed. Outer skirt ( 5 ) can be moved to a second, stressed position in which lugs ( 7,8 ) disengage from slots ( 16,17 ) to allow partial unscrewing until lugs ( 7,8 ) are aligned with the opposite slot ( 17,16 ). The resilient component of the outer skirt ( 5 ) urges it back to the first, rest position and lugs ( 7,8 ) pass through slots ( 16,17 ) due to axial movement of inner skirt ( 3 ) during the partial unscrewing. Thereafter cap ( 1 ) can be fully unscrewed from the container.

[0001] The present invention relates to a container and closure cap andin particular to a container having a child resistant closure cap.

[0002] Child resistant container caps for disinfectant containers andthe like are often of the well known squeeze-and-turn type in which thecap has a skirt which must be squeezed at two diametrically oppositepoints to disengage stops which are formed on the skirt and thecontainer to permit rotation of the cap for removal. This type of capcan be manufactured simply and cheaply because they can be moulded as aone-piece construction.

[0003] Child resistant caps for pharmaceuticals often use an arrangementin which a cap must be pushed downwardly to permit removal. Thesearrangements are generally rather complicated and consequently expensiveto manufacture. Caps which can be operated by pushing down rather thanby being squeezed are preferred by the elderly, however, who find thesqueezing action more awkward.

[0004] Many push-and-turn caps use an inner cap which closes thecontainer and an outer cap which must be pushed down to engage the innercap before the caps are then unscrewed together. However, the use of twocaps necessitates an assembly step in production and generally increasesthe complexity of the design.

[0005] Document U.S. Pat. No. 3,830,391 describes a one-piece closureand a container, in which the closure has inner and outer walls joinedby a resilient bridge. The outer wall has locking lugs which engage stopmembers on the container. In order for the lugs to pass the stop membersthe outer all must be pushed down and then held down whilst the closureis unscrewed to the point at which the inner wall as moved axiallyenough for the lugs to spring above the top members when the outer wallis released.

[0006] The present invention seeks to provide a child resistantcontainer and closure cap which can be operated by pushing down on thecap but which is nevertheless of simple and inexpensive construction.

[0007] Accordingly there is provided a container and a closure captherefor, the container having a screw-threaded neck, the cap having anend panel for closing the neck, an inner skirt depending from the endpanel and having a screw thread for co-operation with the neck thread,and an outer skirt surrounding the inner skirt and being resilientlyconnected thereto, one of the container and the closure having a lockingring with at least one slot therein, the other having at least one lugwhich engages in a slot when the cap is fully screwed on to thecontainer and the outer skirt is in a first, rest position, therebypreventing the cap from being unscrewed, the outer skirt is movable to asecond position in which the resilient connection is stressed and inwhich the lug is disengaged from the slot to allow the closure to bepartially unscrewed until the lug is aligned with the slot,characterised in that the locking ring is adapted to prevent movement ofthe outer skirt back to the first position during partial unscrewingsuch that when the lug is aligned with the slot the resilient connectionurges the outer skirt back to the first position and the lug passesthrough the slot due to axial movement of the inner skirt during thepartial unscrewing, thereafter the cap can be fully unscrewed from thecontainer.

[0008] The resilient connection may comprise a bridge portion whichextends between the inner and outer skirts. By arranging the bridge tojoin the skirts at the closed end of the cap the bridge can form part ofthe end panel and movement between the skirts involves a simple flexingof the bridge.

[0009] A plurality of slots and lugs may be provided; in a preferredembodiment the locking ring has two slots and there are two lugs, bothof which are substantially diametrically opposed to each other. Thisarrangement balances the stresses placed on either side of the capduring use. The number of slots and lugs does not have to be equal.

[0010] In the first position the outer skirt may be axially displaced ofthe inner skirt at their point of connection to the end panel, thebridge portion thereby being inclined. By having an inclined bridgeportion in the first, rest position this presents a raised area on whichto press. This allows for pressing on the cap using the palm of thehand, making applying the required pressure easier.

[0011] The resilience of the bridge portion may be provided by thematerial of the portion itself. For example the portion may be formedfrom an elastomeric material such as polypropylene. The bridge portiondoes not have to be formed from the same material as the rest of thecap, although for simplicity of manufacture this may be the case. Theclosure cap may therefore be a one-piece construction.

[0012] The slots may be longer than the lugs whereby to allow a smooth,continuous unscrewing action as described in more detail below.

[0013] The present invention will now be more particularly described, byway of example, with reference to the accompanying drawings in which:-

[0014]FIG. 1 is a perspective view of a closure cap;

[0015]FIG. 2 is a perspective view of a container for use in conjunctionwith the cap of FIG. 1;

[0016]FIG. 3 is a perspective sectional view through the container ofFIG. 2 shown with the cap of FIG. 1 fully screwed on;

[0017]FIGS. 4A to 4D are schematic vertical sections through thecontainer and closure cap shown in FIG. 3 illustrating the operation ofthe cap; and

[0018]FIG. 5 is a diagrammatic side view of a container according to analternative embodiment.

[0019] Referring first to FIG. 1 there is shown a child resistantclosure cap generally indicated 1 and having a circular end panel 2. Aninner skirt 3 depends from the end panel 2 and is formed with aninternal screw thread 4. An outer skirt 5 also depends from the endpanel 2, radially outwardly of the inner skirt 3 and this creates ahollow interspace between the two skirts 3, 5. At the open end of theouter skirt 5 two diametrically opposed lugs 7, 8 project towards theinterior of the cap. The outer skirt is resiliently connected to the endpanel by an annular bridge portion 20 (shown most clearly in FIG. 3).

[0020] A container for use with the cap of FIG. 1 is shown in FIG. 2 andis generally indicated 10. The container 10 has a cylindrical neck 11formed with an open end and an external screw thread 12 for cooperationwith the screw thread 4 on the closure cap 1. The neck 11 is joined tothe main body 13 of the container by a shoulder 14. At the base of theneck 11 in the region it joins the shoulder 14 an annular locking ring15 extends perpendicular to the main axis of the container 10. Thelocking ring 15 is provided with two diametrically opposed elongateslots 16, 17 which correspond to the lugs 7, 8 of the closure cap 1.

[0021] The interaction of the closure cap 1 and the container 10 isshown more clearly in FIG. 3. When the closure cap 1 is fully screwed onto the container 10 the lugs 7, 8 are engaged in the slots 16, 17 whichprevents the cap 1 from being unscrewed.

[0022] The annular bridge portion 20 is shown to comprise a base 21formed from material which is relatively thin compared to the inner 3and outer 5 skirts and a plurality of radially extending mutually spacedribs 22 which extend from the panel 2 to the outer skirt 5. Thelocalised thinning increases the relative elasticity of the bridgeportion 20 and reduces stress during use. The bridge portion 20 acts asa spring to provide a sprung outer skirt 5 as described below.

[0023] Whilst the knurling provided by the ribs 22 is undesirable fromthe point of the yield of the outer skirt spring, it provides grippingfriction to allow opening of the closure using the palm of the hand,with no squeeze force required.

[0024] The operation of the closure cap 1 and container 10 will now bemore particularly described with reference to FIGS. 4A to 4D. In FIG. 4Athe closure cap is shown fully screwed on to the container asillustrated in FIG. 3. The bridge portion 20 is shown to be upwardlyinclined and the lugs 7, 8 are shown to be engaged in their respectiveslots 16, 17. In this position the closure cap 1 cannot be rotated withrespect to the container because of the engagement of the lugs 7, 8 inthe slots 16, 17.

[0025] Referring now to FIG. 4B, the outer skirt 5 has been moved to asecond position in which the lugs 7, 8 have been disengaged from theirslots 16, 17 and are now below the level of the locking ring 15. In thisposition it will be seen that the bridge portion 20 has moved and is nowin a stressed condition.

[0026] With the lugs 7, 8 disengaged from the slots 16, 17 the closurecap 1 can now be partially unscrewed, as the lugs 7, 8 can pass underthe locking ring 15. The bridge portion is resiliently biassed to thefirst position but is unable to urge the outer skirt upwardly due to theengagement of the lugs 7, 8 under the locking ring 15. As the closurecap 1 is unscrewed the inner skirt 3 begins to move axially as a resultof the screw thread arrangement. The position of the outer skirt 5 isunchanged (because of the engagement of the lugs under the locking ring)but the bridge portion 20 becomes further stressed as shown in FIG. 4C.

[0027] The partial unscrewing of the closure cap 1 continues until thelugs 7, 8 are rotated approximately 180° and they begin to align withthe opposite slot 17, 16. When the lugs 7, 8 are fully aligned with theslots 17, 16 the resilience of the bridge portion 20 urges the outerskirt 5 back to the first position and the lugs 7, 8 pass through theslots 17, 16 due to the axial movement of the inner skirt during thepartial unscrewing. Once the lugs 7, 8 have passed through the lockingring 15 the closure cap 1 can be fully unscrewed from the container 10.

[0028] It will be appreciated that if the slots 16, 17 weresubstantially the same size as the lugs the unscrewing action could notbe continuous. Because the slots 16, 17 are considerably longer (in thisembodiment approximately twice as long) than the lugs 7, 8 theunscrewing action can be continuous; the additional length of the slotsallows the closure cap to be rotated as the lugs 7, 8 move axiallythrough the slots 16, 17. If the slots are the same size as the lugs theunscrewing action would have to be in several stages; the user wouldhave to gently unscrew the closure to the point at which the lugsflicked fully through the slots, during which time no rotation would bepossible.

[0029] When the cap is screwed back onto the closure the lugs snap backinto the slots; the slots prevent over tightening and serve as an endstop for capping machines.

[0030] In other embodiments (not shown) the locking ring is located onthe closure cap and the lugs are located on the container. The principlebehind the operation of such a closure is exactly the same as previouslydescribed.

[0031] In this embodiment the closure cap is injection moulded in asingle piece.

[0032] The container may be made by extrusion blowing using materialssuch as HDPE or by injection stretch blowing using materials such asPET. The closure cap may be made from HPPE, polypropylene or otherelastomeric material.

[0033] Referring now to FIG. 5 there is shown a container 110 accordingto an alternative embodiment. The basic design and function of thecontainer 110 is the same as the container 10 of FIGS. 1 to 4. In thisembodiment the locking ring 115 is slightly upwardly inclined betweenthe slots 116, 117. The inclination makes it easier to unscrew a closurecap (not shown) during the time its lugs pass under the locking ring115. Without inclination, turning of the cap becomes more difficult asthe inner and outer skirts move relative to each other against theresilience of the bridge portion. The inclination of the ring 115reduces the relative movement of the skirts.

[0034] In addition, the locking ring 115 has a stop 118 adjacent each ofthe slots 116, 117. The stops 118 have a ramped surface 119 inclinedaway from the direction of unscrewing, and a sheer face 125 whichdefines the start of the slot.

[0035] The function of the stops 118 is twofold. First, the face 125increases the local width of the locking ring 115 which makes it moredifficult for the closure cap to be forced open, bypassing thepush-and-turn mechanism. Secondly, the ramped surface 119 causes achange in the force required to screw the closure back onto thecontainer just before the lugs engage the slots; the lugs will also passinto the slots with a more definite clicking noise. This informs theuser that the container is fully closed.

1. A container (10) and a closure cap (1) therefor, the container (10)having a screw-threaded neck (11), the cap having an end panel (2) forclosing the neck (11), an inner skirt (3) depending from the end panel(2) and having a screw thread (4) for co-operation with the neck thread(12), and an outer skirt (5) surrounding the inner skirt (3) and beingresiliently connected thereto, one of the container and the closurehaving a locking ring (15) with at least one slot (16,17) therein, theother having at least one lug (7,8) which engages in a slot (16,17) whenthe cap (1) is fully screwed on to the container (10) and the outerskirt (5) is in a first, rest position, thereby preventing the cap (1)from being unscrewed, the outer skirt (5) is movable to a secondposition in which the resilient connection is stressed and in which thelug (7, 8) is disengaged from the slot (16,17) to allow the closure tobe partially unscrewed until the lug (7,8) is aligned with the slot(17,16), characterised in that the locking ring is adapted to preventmovement of the outer skirt back to the first position during partialunscrewing such that when the lug (7,8) is aligned with the slot (17,16)the resilient connection urges the outer skirt (5) back to the firstposition and the lug (7,8) passes through the slot (17,16) due to axialmovement of the inner skirt (3) during the partial unscrewing,thereafter the cap (1) can be fully unscrewed from the container (10).2. A container (10) and a closure cap (1) as claimed in claim 1, inwhich the resilient connection comprises a bridge portion (20) extendingbetween the inner and outer skirts (3,5).
 3. A container (10) andclosure cap (1) as claimed in claim 1 or claim 2, in which the lockingring (15) has two slots (16,17) and there are two lugs (7,8).
 4. Acontainer (10) and closure cap (1) as claimed in claim 2 or claim 3, inwhich in the first position the outer skirt (5) is axially displaced ofthe inner skirt (3) at their point of connection to the end panel (2),the bridge portion (20) being inclined.
 5. A container (10) and closurecap (1) as claimed in any of claims 2 to 4, in which the resilience ofthe bridge portion (20) is provided by the material of the portionitself.
 6. A container (10) and closure cap (1) as claimed in anypreceding claim, in which the slots (16,17) are longer than the lugs(7,8) whereby to allow a continuous unscrewing action.
 7. A container(10) and closure cap (1) as claimed in any preceding claim, in which theclosure cap (1) is a one-piece construction.
 8. A container (10) andclosure cap (1) as claimed in any preceding claim, in which at leastpart of the locking ring 15 is inclined.
 9. A container (10) and closurecap (1) as claimed in anyof claims 2 to 8, in which at least part of thebridge portion (20) is knurled.